Trying to hire the best and the brightest candidates—or even the mediocre and the somewhat dim—has been a massive challenge this year, no matter the size or location of the company. Unfortunately for most recruiters, next year is shaping up to be even tougher as corporate pressure mounts to attract candidates who match the skill sets most in demand.

While there’s no magic bullet to slay this dragon, there are talent acquisition strategies that are proving to be effective, including taking a new look at which groups to target as potential sources for high-quality candidates.

“We’ve found that becoming more flexible in what we seek can make a big difference,” said Michael Kannisto, global director of talent acquisition at New York City-based International Flavors & Fragrances. “We’re looking beyond the obvious options to candidates in adjacent industries and related functions who have similar skill sets,” and then training those new hires in the specifics of the available jobs, he said.

A willingness to look at younger candidates who will need to grow into a position is another popular option, especially since the U.S. Census Bureau estimates that the retirement-age population will grow by 38 percent over the next 10 years. “The aging population will drive up demand in many fields, especially health care, so considering applicants who may be a few years away from what typically is considered a perfect fit for a job can be a great strategy,” said Kyle Kensing, author of a new CareerCast report on the 10 toughest jobs to fill in 2016.

The fact that rapid technical innovation makes many skills obsolete quickly adds to the need to incorporate lots of on-the-job training, and reinforces the notion that a candidate’s once-perfectly matched skills may be outdated by his or her first anniversary on the job.

“If you look at a job like information security analyst, hiring is projected to rise by 37 percent over the next six years, according to the U.S. Bureau of Labor Statistics (BLS), yet the job’s requirements are changing at a rapid pace,” Kensing said. So if a company has a rigid job description for this position, it’s not accounting for evolution within the job that could happen over just the next few months, he added.

Of course, planning a recruitment strategy well before any specific jobs need to be filled is the smartest strategy, yet one that hasn’t been adopted widely given the just-in-time nature of many industries.

“Through workforce planning and predictive analytics, it’s really critical to determine ahead of time what your hiring needs will be,” said Kannisto. “Nursing is a great example: You can look at expected retirements among your staff to start planning recruitment efforts three years before you need those hires.”

Efforts to recruit upstream by forging relationships beyond traditional college sources also can be effective, he added. Consider creating programs for high school students, as well as with diversity organizations that work with younger age groups, as a great way to help meet recruiting goals well beyond next year, Kannisto said.

And for those more worried about the near future, these are the 10 jobs that CareerCast expects will be especially difficult to fill next year due to a range of reasons, including BLS-projected talent shortages in each field, retirements due to an aging workforce and above-average growth in demand:

Data Scientist

Roughly 6,000 companies are expected to hire for an estimated 4.4 million IT jobs with direct ties to data analysis next year, reported CareerCast via Stamford, Conn.-based Gartner. Data science’s hiring boom is tricky to measure, say analysts, because the field is so new that the BLS doesn’t yet track specific hiring needs. In addition, the skill sets and responsibilities are still being defined at many companies, which likely will increase the recruiting challenge as hiring managers redefine what they seek on a regular basis.

Electrical Engineer

While demand for electrical engineers is expected to be strongest in Chicago, Houston and San Diego, the greatest supply of candidates will likely be in Los Angeles and New York, thus creating an imbalance, reported Randstad US, which also estimates that there are currently 17 openings for every electrical engineering candidate.

General and Operations Manager

To meet the expected 12.4 percent growth in demand that the BLS anticipates by 2022, recruiters will have to get busy soon. That growth rate translates into 613,000 open positions to fill for general and operations managers over the next seven years.

Home Health Aide

Hiring is projected to rise by 48 percent over the next seven years, which the BLS says is a direct result of the aging population. Nearly 600,000 positions will need to be filled to meet the expected demand, while the low median salary of $20,820 limits the scope of the candidate pool.

Information Security Analyst

The proliferation of cloud-based technology is a driving force in the need for this job. Microsoft reported that by the beginning of next year, North American companies will need to employ at least 2.7 million cloud-computing workers, including information security analysts, and labor analysts say the supply can’t meet that demand.

Marketing Manager

With the explosive growth in digital marketing and an already high average annual salary of $127,130, marketing managers are in very short supply, reported the BLS. Looking to new college graduates to help fill the pipeline won’t suffice, as marketing is one of the skill sets most in demand by college recruiters, according to the National Association of Colleges and Employers.

Medical Services Manager

The requirements for this position overlap the nation’s highest labor shortage industries, as estimated by BLS: health care, social assistance and professional business services. The BLS projects 73,300 new hires will be needed in the field by 2022, and predicts a 23 percent overall increase in employment.

Physical Therapist

The American Physical Therapy Association estimates that in 2016, demand for full-time physical therapists will exceed 229,000, with a pool of candidates of around 196,000—creating a gap of 33,000 unfilled jobs. Like other health care fields, demand is up due to greater accessibility to health insurance and the aging population.

Registered Nurse

The BLS projects a 19 percent growth rate by 2022, but it also estimates that 525,000 currently working registered nurses will have to be replaced due to retirements, which puts the total number of new hires anticipated at 1.05 million over the next seven years. In addition, the average age of working nurses is expected to rise to 44.6 from the current 42.7.

Software Engineer

The Conference Board estimates there will be three jobs available for every new college graduate from a computer science program in 2016. Not surprising, since the BLS estimates 222,600 software engineering jobs will need to be filled by 2022.